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Aluminum alloys such as Al 5052-H32 are widely used in the aerospace industry due to
their excellent corrosion resistance, moderate strength, and good weldability. In this research, a
comparative investigation was conducted on riveted and TIG-welded lap joints made from Al
5052-H32 to assess their mechanical performance and microstructural characteristics. TIG
welding, performed using ER4043 filler wire, was explored as an alternative to traditional riveting
in non-structural aircraft components such as access panels, enclosures, and ventilation systems.
Tensile testing revealed that welded joints exhibited superior strength, with failures consistently
occurring in the base material rather than the joint, indicating strong fusion integrity. In contrast,
riveted joints failed through separation of the rivet head, highlighting a limitation in their loadbearing capacity.
Microhardness testing and optical microscopy were used to analyze the fusion zone (FZ),
heat-affected zone (HAZ), and base material (BM) in welded joints, as well as the regions adjacent
to rivet holes. Results showed increased hardness in both the FZ and HAZ, attributed to localized
grain refinement and solidification effects from the welding process. In riveted joints, slight
hardness variations were observed near the rivet due to compressive plastic deformation. The
microstructure images confirmed the presence of partially recrystallized grains in the HAZ and
fine equiaxed grains in the FZ. These findings demonstrate that TIG welding can offer
mechanically superior and metallurgically favorable joints for selected aircraft applications,
provided that design constraints and service conditions are appropriately considered.